This invention relates in general to a quick-disconnect coupling for a heavy-duty machine to enable the quick coupling and decoupling of coupling members on a boom and a stick having a tool so that the machine may be easily used for sticks having different working tools, and more particularly to a power coupling having coupling elements carried by the coupling members for connecting a source of power from the machine to the stick that facilitates the proper mating of the coupling elements when the coupling members of the stick and boom are brought into engaging relation.
Heretofore, it has been well known to provide a quick connect and disconnect coupling between the boom of a heavy duty machine and a stick, as described in U.S. Pat. Nos. 4,938,651; 5,108,252 and 5,484,250. These prior known coupling members include the use of quick connect/disconnect coupling elements for connecting a power source from the boom to a power device on the stick. However, problems, such as the breaking and/or blowing of seals in hydraulic fluid coupling elements leading to hydraulic fluid leakage and pressure loss, sometimes resulted from the rigid mounting of the connecting coupling elements and the inability of the elements to properly align and couple and decouple. Additionally, even if the seals remained intact, a substantial amount of fluid may be lost in the coupling and uncoupling process of the coupling elements. Moreover, damage to any coupling elements often occurred during the coupling operation.
Further, due to sun exposure, the coupling elements and hydraulic lines may experience a thermal buildup, or an increase in pressure when hydraulic fluid is used. Heretofore, it has been known to use diverter valves in an attempt to accommodate such surges in pressure during the coupling of power coupling elements between the boom of a heavy-duty machine and a stick to minimize fluid loss. However, diverter valves require a mechanical operation with a specific tool and are not always reliable during coupling and uncoupling operations.
The power coupling of the present invention is an improvement over the above referred to prior known couplers to minimize the problems of losing hydraulic fluid when coupling and decoupling hydraulic coupling elements, and damage to any coupling elements during the coupling and uncoupling operations. In particular, the power coupling of the invention includes one coupling element mounted in an oversized hole of a mounting plate to allow orbital movement on the plate of one coupling member along X and Y axes, and the other coupling element gimbal-mounted on a plate of the other coupling member along a Z axis to facilitate the proper alignment between the power coupling elements when the coupling members are brought together. Thus, the coupling elements are mounted to accommodate X, Y and Z alignment when the elements are coupled and decoupled. Further, bumpers are provided in the mounting structure of the elements to compensate for wear of the coupler member engaging faces, and adjustment along the Z axis. Still further, the present invention includes an accumulator for the hydraulic lines to accommodate any surge pressure generated during the coupling and decoupling operations. The X, Y and Z alignment capability and the accumulator facilitate coupling and decoupling under high pressure and eliminate the need for a diverter valve.
It is therefore an object of the present invention to provide a new and improved quick-disconnect power coupler with coupling members between a boom of a heavy-duty machine and a stick having power coupling element mountings to substantially eliminate power coupling element damage and/or spillage of hydraulic fluid.
A further object of the present invention is to provide a new and improved power coupling for a quick-disconnect coupling that utilizes a gimbal-mounted power coupling element on one coupling member for Z axis alignment and a coupling element mounted on the other coupling member in an oversized hole of a plate on the other coupling member for X and Y axes alignment to allow for the coupling elements to move relative to one another during coupling and decoupling to assist in the proper engagement of the coupling elements and avoid loss of hydraulic fluid.
Another object of the present invention is to provide a hydraulic power coupling for a quick-disconnect coupling mounted for X, Y and Z alignment that minimizes or eliminates the loss of hydraulic fluid during the coupling and uncoupling operations.
Still another object of the present invention is to provide mountings for power coupling elements that compensate for wear between coupler faces.
Yet another object of the present invention is to provide hydraulic coupling elements that accommodate surges of hydraulic pressure during the coupling and decoupling process, thereby substantially eliminating spillage of hydraulic fluid.
Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts.